The NHGRI Microarray Core provides resources, cost-effective and time-efficient services, advice and technical support to meet the needs of NHGRI, NINDS, and NIMH investigators related to genomics research. The services primarily focus on gene expression and genotyping technologies. Researchers utilize the expertise, protocols and instrumentation available in the Core laboratory. The Core adapts readily as new technologies emerge, and aids in both performing laboratory services as well as experimental design. In the past year gene expression services were provided using mostly commercial (Affymetrix, Agilent and Illumina) arrays. In-house arrays, however, were available for zebrafish expression studies. The Core provided expression analysis using >1600 arrays (Affymetrix, Agilent, Illumina and In-house oligos chips). The investigators utilized the expression services (total RNA and microRNAs) to gain insight into a variety of human disease conditions, including Niemann-Pick disease, type C (NPC), melanoma, endometrial cancer, Progeria syndrome, type II diabetes, blood malignancies, and Gaucher disease. We have also been involved in expression studies of immune cell characterization and normal skin bacterial flora. In addition, studies of disease models and developmental changes in the mouse have been done. Studies include mouse lung sensitivity due to to dust mites, and glial cell migration. With regard to human disease a variety of studies have been done including those aimed at understanding expression profiles associated with schizophrenia, autism and other behavioral phenotypes. Finally, zebrafish germ layer development, sex differentiation, and hair cell regeneration have also studied this year employing the gene expression technologies of the Array Core. SNP-based microarray technologies from Affymetrix and Illumina were used by the Core to provide genotyping services critical for genome wide association (GWAS) studies. These services were applied for a variety of studies related to human neuronal diseases, cancer, and diabetes. In addition, the core optimized SNP chip technologies related to the canine model, and as a result several studies were undertaken to find genes that control morphologic variation across the species, as well as breed susceptibility to various forms of cancer including gastric, histocytic sarcoma, transitional cell carcinoma of the bladder, and squamous cell carcinoma. The dog studies alone involved running over 1,500 SNP chips. In summary, the NHGRI Array Core has met the needs to multiple investigators in three Institutes for both expression and SNP-based genotyping studies. A number of publications arose from this work and Core staff have been listed as authors on nine and cited in the acknowledgements of several others.